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Move one matchstick to make an equality.enter image description here

Question made by me (Is this too easy?)

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  • $\begingroup$ First idea was: 9 - 5 < 5. But I believe your request of an equality wouldn't allow this inequality. $\endgroup$ Jun 3 '20 at 9:07
  • $\begingroup$ @SwissFrank: To be honest I would also count that as requiring two moves, one for each of the = matches since you need to rotate both. $\endgroup$
    – Flater
    Jun 3 '20 at 10:50
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Here's one way:

enter image description here

For the image-impaired:

5 = 5 = 5

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    $\begingroup$ Correct! I was thinking about this answer! $\endgroup$ Jun 1 '20 at 2:27
  • $\begingroup$ Congrats! You earned Enlightened, Good answer and, Nice answer for answering this question! $\endgroup$ Jun 2 '20 at 5:00
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    $\begingroup$ Technically, that is not "a correct equation", but rather, a few correct equations... $\endgroup$ Jun 2 '20 at 13:12
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    $\begingroup$ But the two = signs are not at the same height... I dismissed this solution in my mind, since I'd have to move two matchsticks to make the = match the other =. @ScottMiller's solution should be the accepted answer, since it is truly moving only one matchstick to make an equality (although, it's definitely not "easy"!). $\endgroup$
    – LHM
    Jun 3 '20 at 21:20
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Another solution:

Interpreted in hexadecimal: A-5=5

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  • $\begingroup$ Love it. I found the easy one and move on... this is next level creativity though, well done. $\endgroup$
    – tmpearce
    Jun 3 '20 at 2:56
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Another solution is to

move the center bar of the 9 to the lower left position of that digit to make a 0

and then

look at it from the other side of the table (i.e. rotate it 180 degrees), so it appears to say $5=5-0$

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    $\begingroup$ Isn't doing the second part of that equivalent to moving all of the match sticks? $\endgroup$
    – Kevin
    Jun 1 '20 at 22:34
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    $\begingroup$ Not if they're on a flat table. $\endgroup$
    – shoover
    Jun 2 '20 at 1:31
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    $\begingroup$ @KevinWells: It depends on how much the puzzle constrains lateral thinking. Free rotations is usually not in the spirit of these puzzles but I wouldn't blanket exclude lateral solutions either as they are an interesting style in and of themselves. $\endgroup$
    – Flater
    Jun 3 '20 at 10:51
  • $\begingroup$ @Flater I would expect that kind of question to include the lateral thinking tag, but I get that some people prefer to look at all puzzles through that lens $\endgroup$
    – Kevin
    Jun 3 '20 at 18:40
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One more possibility:

Move the upper-left stick of the 9 to cross the equals sign so we get 3 - 5 ≠ 5

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    $\begingroup$ You should not use the answer unequal sign. $\endgroup$ Jun 2 '20 at 1:07
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    $\begingroup$ The answer specifically says "equality"... that wouldn't be an equality... $\endgroup$ Jun 3 '20 at 9:04
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This is the first thing that came to mind (when the question was originally posed as "Move one matchstick to make an equation"):

enter image description here

Written out:

5 - 5 ≠ 5

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    $\begingroup$ Wait, your picture is different from your written out answer! $\endgroup$ Jun 2 '20 at 1:48
  • $\begingroup$ Seems like you notice the word “equality”. You formed an inequality. $\endgroup$ Jun 2 '20 at 3:16
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    $\begingroup$ @CulverKwan: I don't see the word "equality". I see the word "equation". I've always considered inequalities to be equations, as you can still manipulate them using the same rules. Most of the internet seems to agree with you, but if I've ever heard this distinction, I don't remember it. My concept was to move the bottom bar of the 9 to form a not-equals sign, and there's another version elsewhere, so apparently at least 3 people on Earth think of this as an equation. $\endgroup$
    – MichaelS
    Jun 3 '20 at 2:12
  • $\begingroup$ @MichaelS, I will edit the question. $\endgroup$ Jun 3 '20 at 2:13
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You can also make it:

9-4=5

just by

moving the top match from the first 5

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    $\begingroup$ You would need to move the bottom one too. $\endgroup$
    – rtaft
    Jun 2 '20 at 14:29
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    $\begingroup$ It would still be readeable with the bottom one there, at least in my opinion. I think there are a bunch of answers to this. $\endgroup$
    – JustZig
    Jun 2 '20 at 14:38
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    $\begingroup$ It may still be readable but IMO the "4" with a bottom bar is not a number. When have you ever seen a 4 drawn with a bar on the bottom? $\endgroup$
    – mittmemo
    Jun 2 '20 at 21:13
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    $\begingroup$ image.freepik.com/free-photo/… $\endgroup$
    – JustZig
    Jun 3 '20 at 13:14
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I'm not familiar with the process by which y'all are rendering these (some type of MatchstickML based on TeX and MathJax?) But as there is no specified alignment and you assume they may only be vertical or horizontal, if you move the \U+002D matchstick to the initial 9, one could consider that that a crossed or dotted zero, (as all zeros should be), leaving something akin to

0̸5=𝟻

(Something akin to padding a simple 8-bit decimal in UTF-16 with a BOM, for ridiculous encodings like that.

P.S. I'm honounered to be Lizzy, but where's Colonel Brandon?

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  • $\begingroup$ No, it is to complicated. $\endgroup$ Jun 3 '20 at 0:51
  • $\begingroup$ "I'm not familiar with the process by which y'all are rendering these (some type of MatchstickML based on TeX and MathJax?)" These are all just plain old images, created probably with something like Paint. $\endgroup$
    – zovits
    Jun 3 '20 at 13:00

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